The Daily Telegraph can disclose that the Conservative and Unionist Association in Stirling, the city hosting the gathering, have written to Ms Davidson complaining that her promise of an extra package of powers was a “serious volte face”.

Members have expressed their “dismay” at their leader’s recent change of stance after she was elected on a platform of drawing a constitutional “line in the sand”.

Conservative sources said there was also widespread disillusionment about Ms Davidson’s refusal to allow a debate on the subject at the conference, which starts tomorrow.

They expressed their frustration about being forced to debate further powers away from the main conference hall as part of the gathering’s fringe.

“We should be debating this opening but to banish this topic from the conference floor and to have it debated in a hotel room round the corner makes a mockery of Ruth’s promise to make conference a more meaningful and participative body,” one said.

Another said her refusal to allow discussion on further devolution made Ms Davidson appear “weak”. She promised in her first Scottish Tory conference speech as leader a year ago to "bring back proper debate within our ranks".

Sources said it was “rare” for an association to take the step of writing a letter to the Scottish Tory leader but such was their anger that they passed a motion as their recent annual general meeting.

Members of the Stirling party expressed their dissatisfaction at their annual general meeting on May 17. It is understood those who voted for Ms Davidson in the 2011 leadership contest were particularly unhappy.

However, even those who backed her main opponent, Murdo Fraser, who supported the devolution of more powers, were confused about her u-turn.

The row broke out after the Daily Telegraph disclosed last week there was deep disillusionment among Ms Davidson's front bench about her performance, particularly at First Minister's Questions.

This newspaper reported last weekend that some MSPs are also unhappy at her refusal to debate further devolution at conference, although others said the focus should remain on fighting independence.

Ms Davidson has said she does not want to "tie the hands" of Lord Strathclyde, the former leader of the House of Lords, who has been charged with drawing up a new package of powers for Holyrood.

However, Scottish Labour allowed a debate on further devolution at its conference in April despite also having a commission working up proposals on the subject.

A Scottish Tory spokesman said: “Ruth replied to the letter at the weekend. She is aware there are strong opinions on this subject right across the spectrum and every party association, including Stirling, will have the opportunity to contribute to Lord Strathclyde’s commission.”